\documentclass[12pt, a4paper, reqno, oneside]{book}
\usepackage{amsmath,amsxtra,amssymb,latexsym, amscd,amsthm}
\usepackage{indentfirst}
\usepackage{color}
\usepackage[utf8]{vietnam}
\usepackage{amsmath}
\usepackage[mathscr]{eucal}
\usepackage{amsfonts}
\usepackage{graphics}
%\input setbmp
\usepackage[unicode]{hyperref}
\usepackage{titledot}
\titlename{Chương}
%+ Can le van ban
\setlength{\oddsidemargin}{0in}
\setlength{\textwidth}{6.in}
\setlength{\topmargin}{-0.5in}
\setlength{\textheight}{9.25in}
\renewcommand{\baselinestretch}{1.5}

%+ Dinh nghia mot so ky hieu toan hoc.
\def\B{\mathscr B}
\def\one{\mathbf 1}
\def\R{{\mathbb R}}
\def\LL{{\mathbb L}}
\newcommand\abs[1]{|#1|}
\newcommand\set[1]{\{#1\}}
\newcommand\norm[1]{||#1||}
\DeclareMathOperator{\vrai}{vrai}
\DeclareMathOperator{\const}{const}
\newcommand{\eoproof}{\hfill $\square$}
\newcommand{\spro}[1]{\left<#1\right>}
\newcommand{\argmin}{\arg\min}

\renewcommand{\theequation}{\arabic{chapter}.\arabic{section}.\arabic{equation}}
\newtheorem{lemma}{\bf Bổ đề}[section]
\newtheorem{theorem}{\bf Định lý}[section]
\newtheorem{proposition}{\bf Mệnh đề}[section]
\newtheorem{corollary}{\bf Hệ quả}[section]
\newtheorem{definition}{\bf Định nghĩa}[section]
\newtheorem{remark}{\bf Chú ý}[section]

%+ Bat dau tai lieu tai day.
\begin{document}
%+ ====================================================
\makeatletter
\renewcommand{\ps@myheadings}{
\renewcommand{\@oddhead}{\textsf{Khóa luận tốt nghiệp - ngành toán tin ứng dụng}\hfil\textrm{\thepage}}
\renewcommand{\@oddfoot}{\textsf{Trịnh Văn Hải, Lớp K49A2, Toán tin ứng dụng}\hfil}
}
\makeatother 

%+ Page style
\newpage
\input bialuanan

\pagestyle{plain}
\input loicamon

\tableofcontents
\newpage
\input loimodau

\newpage
\input {chuong1}

\newpage
\input {chuong2}

\newpage
\input {chuong3}

\newpage
\input {Phuluc}

%\newpage
\input {Ketluan}

\newpage
\input {Tailieuthamkhao}

\end{document}